Pairing an Apple (bluetooth) wireless keyboard with multiple computers
I have found that the following procedure works fine to connect one Apple wireless keyboard with 2 computers (could be done with more).
1. Pair keyboard with computer A
2. Disconnect keyboard (do not remove! only disconnect)
Note: To disconnect go to System Preferences -> Bluetooth -> Select keyboard device and next to the - (minus) sign there is a tools sign with more options one of them being "Disconnect"
3. Switch off keyboard and pair with computer B
And then ... to connect back with computer A:
4. Disconnect keyboard with computer B
Remember do not remove, cos it will mean that next time you need to pair again, entering the digits.
5. Switch off the keyboard (pressing 4 secs)
6. Turn on the keyboard pairing (pressing again the keyboard for 4 secs until the light turns on blinking)
7. On computer A: Go to Bluetooth, select the keyboard and options and select Connect.
and voilà, you don't need to "re-pair" (searching and entering digits) only re-connect.
I have done it and it works with a Mac Mini (Mac OS 10.6 Snow Leopard) and a Mac Book Pro (Mac OS 10.7 Lion)